摘要:

Observations of ion-bombardment-induced surface modifications on crystalline copper substrates have been made using scanning electron microscopy. The delineation and development of grain boundary edges, faceted and terraced etch pits and small-scale ripple structure, together with the formation of faceted conical features, have all been observed on low and high purity polycrystalline substrates. In general, the density of such surface morphological features, although variable from grain to grain, is higher in the proximity of grain boundaries. In particular, cones are only found within regions where other surface erosional features are present and it would appear that the development of these other surface features is a pre-requisite to cone generation in high-purity crystalline substrates. We suggest the operation of a defect-induced mechanism of cone formation whereby sputter elaboration of bulk defects (either pre-existing or bombardment-induced) leads to the formation and development of surface features which, in turn, may intersect and result in the generation of cones.

ISSN:0033-7579    

DOI:10.1080/00337577708233065

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A systematic investigation of implantation damage by various heavy tons (Z1⩾ 7) in the energy range 10-60 keV has been undertaken in Si and Ge at 50 and 300 K. In several cases, diatomic ions having the same energy per atom as the corresponding monatomic ions were also used. The results are interpreted in terms of the mean deposited energy density within each collision cascade. In all cases, the generally accepted collision cascade theory grossly underestimates the amount of observed damage and, at the higher deposited energy densities (i.e., Θ ≳ 0.1 eV/atom), non-linear effects provide strong evidence for the existence of spike phenomena.

ISSN:0033-7579    

DOI:10.1080/00337577708233066

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The results of experimental study of the spatial distributions of the 30 keV argon ions scattered by the (100) face of a copper crystal are presented. The character of spatial distributions of the scattered ions at small ejection angles has been found to significantly differ from that observed under the conditions of strong focusing.

ISSN:0033-7579    

DOI:10.1080/00337577708233067

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Channeling effect measurements using MeV He ions were used in the study of 80 keV, R.T. arsenic implants in silicon. The implantation disorder and the atom location of arsenic atoms were studied as a function of sequential anneals in the temperature range 600-900°C for the doses 0.7, 1.5 and 4 × 1014cm−2. Values for the amorphization dose, average damage depth and spread of damage depth are reported and discussed. From the atom location measurements, it appears that no appreciable arsenic fraction is present at regular tetrahedral interstitial sites in the silicon lattice, following different isochronal (30 minutes) annealing steps at temperatures ranging from 600° to 900°C. The arsenic substitutional fraction was determined and the data correlated with conductivity and Hall effect measurements previously performed for the implantation dose of 0.7 × 1014ions - cm−2. The results of the analysis seem consistent with a model for the physical process responsible for the electrical activation of implanted arsenic, consisting in the dissociation of defects constituted by arsenic atoms in a cluster or complex with vacancies into monoatomic uncompensated substitutional arsenic. This model is discussed also with respect to the results of kinetics studies.

ISSN:0033-7579    

DOI:10.1080/00337577708233068

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The prominent bands of H centers in undoped CaF2, SrF2and BaF2crystals, irradiated at low temperature (18 K) by reactor neutrons have been observed with optical absorption measurements at 300, 307 and 330 nm respectively.

ISSN:0033-7579    

DOI:10.1080/00337577708233069

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A study has been made of d+ion implantation in Si(111) at 100 K and 300 K. Deuterium depth profiles as a function of fluence were obtained using a method based on observing the energy spectra of the tritons and protons from the D(d, p)T reaction induced with a deuteron beam. Profiles at 300 K show two distinct regions in the target. For a fluence of 4 × 1015d+/cm2the surface region which extends over the first half of the deuteron range contains little deuterium (∼ 0.3 atomic %) while a relatively large amount (∼ 5 at. %) is retained in a buried layer. Typical scanning electron micrographs taken following implantation are presented. They show the deeper layers to be highly damaged. In striking contrast, the surface region shows little observable damage even for doses exceeding 1019d+/cm2. Deuterium diffusion coefficients are estimated for silicon under irradiation conditions.

ISSN:0033-7579    

DOI:10.1080/00337577708233070

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The channeling technique has been used to determine the disorder distributions in silicon bombarded at 45 K with a 10-80 keV H+, He+, Li+, B+, C+, N+, O+, and Ne+(v < eI/h). Comparison of these measured distributions with calculated deposited energy distributions obtained using a Monte-Carlo technique yields quantitative data on the inelastic stopping cross-section. For random incidence we find that the inelastic stopping cross-section for silicon is larger than the Lindhard value and exhibits aZ1dependent variation in qualitative agreement with earlier foil transmission experiments.

ISSN:0033-7579    

DOI:10.1080/00337577708233071

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

In an experiment which combines photon detection and secondary ion analysis, the influence of single crystal structure on excited particle emission from a (100) Al surface bombarded with 50 KeV Ar+ions is investigated. The measurements show that both photon and secondary ion yields exhibit characteristic transparency effects when the Al crystal is bombarded under channeling conditions. The angular width of the (110) channel was measured as 16 degrees for the photon yields for types I, II and III spectral lines and Al+and Al++secondary ions. The minimum yield for photons was found to depend upon the excitation energy of the excited upper state of the optical transition studied and the minimum yield for ions was dependent upon the kinetic energy of the detected particle. Furthermore the effect of oxygen on the photon and secondary ion yields was studied under conditions in which the incident ion was channeled.

ISSN:0033-7579    

DOI:10.1080/00337577708233072

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Measurements of the lattice disorder resulting from equal atom-dose implants of various molecular and monatomic ions have been obtained in germanium, using the Rutherford backscattering/channeling-effect technique. As in the earlier studies in silicon, the molecular beams produce significantly more damage than the same atomic fluence of monatomic ions, indicating that damage production depends not only on the total amount of deposited energy but on its localized concentration. Reflection electron diffraction and replica techniques have also been used to provide information on the structure of damage and on the surface topography of the implanted germanium.

ISSN:0033-7579    

DOI:10.1080/00337577708233073

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The sputtering coefficient of polycrystalline gold bombarded by 10–40 keV Ar+ions has been measured as a function of total ion dose and shown to exhibit oscillations in magnitude between 30 and 100%. Possible experimental errors which would give rise to such an oscillation have been considered, but it is apparent that these factors are unable to explain the measurements. It is proposed that a change in the Sublimation Energy associated with either bulk damage or formation of surface topographical features arising during ion bombardment may be responsible for the observed variations in sputtering coefficient.

ISSN:0033-7579    

DOI:10.1080/00337577708233074

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor